“Excuse me, where’s the section on altered dominant chords, please?”
All of us are always learning (well, hopefully most of us are…), but it’s not big-headed to take pride in what you do.
Here’s a little parable (with apologies to Jorge Luis Borges). Imagine you’re walking down an enormous corridor in a library that stretches on and on into the distance. You’re reading the books as you go, and all you can ever see ahead is more shelves crammed with books that you haven’t read. Sometimes you’re inspired and motivated by what’s ahead and still to be discovered, sometimes the sprawling vista of what you have yet to learn gives you the blues.
All those books you haven’t read… But have you ever stopped, sat down for a moment and looked back along the corridor at the view of all the books you have read?
This isn’t intended as a prescription for complacency or arrogance, rather a mild corrective against self-flagellation. Self-awareness cuts both ways. And remember, the world is full of people who are quite happy to talk you down – you don’t need to do it to yourself.
Jason Lyon on Music 
Well said, Sir